Identification Of Egg Origin Based On Stable Isotopes And Mineral Elements

Eggs occupies an important position in the diet of Chinese residents,and the place of origin of the eggs is an important factor that affects residents' decision to purchase.In recent years,there have been frequent occurrences of microbial contamination of eggs and bird flu and other diseases.The development of egg origin traceability technology is of great significance to protect the rights and interests of consumers and maintain food safety.Stable isotope technology and mineral element fingerprinting technology are widely used in the traceability of the origin of agricultural products.The two technologies can characterize the feed source and breeding methods of animal products,and are important tools for identifying the origin and breeding methods of animal products.In this paper,eggs from five provinces in China are used as experimental materials,and stable isotope technology combined with mineral element fingerprinting technology is used to construct the traceability model of egg origin in five provinces and the traceability model of egg origin in small regions,and establish the discriminant model of free-range eggs and caged eggs.Compare the differences between the contents of 17 mineral elements and the ratios of 3 isotopes in eggs from 5 provinces in China.The main findings are as follows:(1)Using eggs from five provinces in China as experimental materials,establish an elemental analysis-stable isotope ratio mass spectrometer(EA-IRMS)method for determining ?13C and ?15N in egg yolk and an isotope water balance instrument(EQ-IRMS)for determining 8180 in egg yolk,Inductively coupled plasma mass spectrometer(ICP-MS)was used to determine the contents of 17 mineral elements in eggshell membranes of eggs in five provinces.(2)Based on stable isotope technology and mineral element fingerprinting technology,the origin traceability research of egg samples from 5 provinces in my country.Duncan's multiple comparisons were used to analyze the differences in stable isotopes and mineral elements in eggs from five provinces in my country.The analysis results showed that Al,B,Ba,Co,Cr,Fe,Li,Mg,Mn,Mo,Ni,Rb,Sn,Sr,Ti,The 19 indicators of Zn,Sc,?18O and ?15N are significantly different among egg samples from five provinces in my country(P<0.05).Combining principal component analysis(PCA),support vector machine(SVM)and linear discriminant analysis(LDA)to construct a traceability model for the origin of eggs in five provinces in China.The results show that the correct rate of the SVM model is 78.95%,the correct rate of the original classification of the LDA model is 86.3%,and the correct rate of cross-validation is 84.5%.The LDA model is better than the SVM model.(3)Based on stable isotope technology and mineral element fingerprinting technology,the origin traceability research of egg samples from 4 cities in Shandong Province of my country.Duncan multiple comparisons were used to analyze the stable isotope and mineral element content in eggs from 4 cities in Shandong Province.The analysis results showed that Al,B,Li,Mg,Mo,Rb,Sn,Sr,Ti,Zn,Sc,The 14 indexes of ?13C,?15N,and ?18O all have significant differences(p<0.05).Combining principal component analysis(PCA)and linear discriminant analysis(LDA)to construct a traceability model for the origin of eggs in 4 cities in Shandong Province.The results show that the original classification accuracy of the LDA model is 78.4%,and the cross-validation accuracy is 56.9%.(4)Research on the identification of free-range eggs and caged eggs in Shijiazhuang City based on stable isotope technology and mineral element fingerprinting technology.The t-test was used to compare and analyze the differences in mineral elements and isotopes between free-range eggs and caged eggs.The analysis results showed that the Ba,Li,Sn,Zn,Sc element content in the shell membrane of free-range eggs and the ?15N value in the yolk were significantly higher than those in the cage.Raise eggs(P<0.05).Combining Principal Component Analysis(PCA),Orthogonal Partial Least Square Discriminant Analysis(OPLS-DA)and Linear Discriminant Analysis(LDA)to construct a discriminant model for free-range and caged eggs in Shijiazhuang City.The results show that the initial verification accuracy of the LDA model is 100%,and the cross-validation accuracy is 80%.The key factors affecting the identification of free-range eggs and caged eggs in Shijiazhuang City were screened out as Mg,Fe and Zn.